python_extension/python-nacl.c

   1
   2 #include <Python.h>
   3
   4 /* TODO: get this from installed headers */
   5 #include "../../../glibc/sysdeps/nacl/nacl_syscalls.h"
   6
   7 /* TODO: get these from libnacl rather than hardcoding them */
   8 static int (*imc_sendmsg)(int fd, const struct NaClImcMsgHdr *msg, int flags) =
   9   NACL_SYSCALL_ADDR(NACL_sys_imc_sendmsg);
  10 static int (*imc_recvmsg)(int fd, struct NaClImcMsgHdr *msg, int flags) =
  11   NACL_SYSCALL_ADDR(NACL_sys_imc_recvmsg);
  12
  13
  14 static PyObject *py_imc_sendmsg(PyObject *self, PyObject *args)
  15 {
  16   int fd;
  17   char *data;
  18   int data_size;
  19   struct NaClImcMsgIoVec iov;
  20   struct NaClImcMsgHdr msg;
  21
  22   if(!PyArg_ParseTuple(args, "is#", &fd, &data, &data_size))
  23     return NULL;
  24   iov.base = data;
  25   iov.length = data_size;
  26   msg.iov = &iov;
  27   msg.iov_length = 1;
  28   msg.descv = NULL;
  29   msg.desc_length = 0;
  30   imc_sendmsg(fd, &msg, 0);
  31   Py_INCREF(Py_None);
  32   return Py_None;
  33 }
  34
  35 static PyObject *py_imc_recvmsg(PyObject *self, PyObject *args)
  36 {
  37   int fd;
  38   char buffer[1024];
  39   struct NaClImcMsgIoVec iov;
  40   struct NaClImcMsgHdr msg;
  41   int result;
  42
  43   if(!PyArg_ParseTuple(args, "i", &fd))
  44     return NULL;
  45   iov.base = buffer;
  46   iov.length = sizeof(buffer);
  47   msg.iov = &iov;
  48   msg.iov_length = 1;
  49   msg.descv = NULL;
  50   msg.desc_length = 0;
  51   result = imc_recvmsg(fd, &msg, 0);
  52   if(result >= 0)
  53     return PyString_FromStringAndSize(buffer, result);
  54   else {
  55     Py_INCREF(Py_None);
  56     return Py_None;
  57   }
  58 }
  59
  60 static PyMethodDef module_methods[] = {
  61   { "imc_sendmsg", py_imc_sendmsg, METH_VARARGS,
  62     "NaCl imc_sendmsg() syscall: sends a message" },
  63   { "imc_recvmsg", py_imc_recvmsg, METH_VARARGS,
  64     "NaCl imc_recvmsg() syscall: receives a message" },
  65   { NULL, NULL, 0, NULL }  /* Sentinel */
  66 };
  67
  68 void initnacl(void)
  69 {
  70   Py_InitModule3("nacl", module_methods, "NaCl syscall wrappers");
  71 }